1. Field of the Invention
The invention relates to an antenna, and more particularly to an inverse F antenna comprising spiral structure.
2. Description of the Related Art
FIG. 1 shows a conventional antenna 10 comprising a ground element 1, a conductive element 2, a transmission element 3, and a coaxial cable 4. The conductive element 2 is connected to the ground element 1. The transmission element 3 is connected to the conductive element 2. The coaxial cable 4 is electrically connected to the ground element 1 and the conductive element 2.
Conventionally, the length of the transmission element 3 is determined according to the wavelength of the wireless signal transmitted by the antenna 1. The length of the transmission element 3 thus cannot be reduced. As well, the conventional antenna 10 requires additional a matching element to modify impedance thereof, and volume of the antenna 10 is increased.